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2. Removal and Replacement of Expansion Valve
IMPORTANT
1. Sometimes moisture in the refrigerant circuit exceeds the drier capacity and
freezes up at the expansion valve. Always install a new drier every time the
sealed refrigeration system is opened. Install the new drier with the arrow on
the drier in the direction of the refrigerant flow.
. It is advisable to change out both expansion valves when replacing an
expansion valve.
3. Connect the expansion valve bulb to the corresponding refrigeration circuit
suction line.
1) Turn off the power supply.
) Remove the panels.
3) Recover the refrigerant and store it in an approved container.
4) Remove the insulation and the expansion valve bulb on the suction line.
5) Remove the expansion valve cover and disconnect the expansion valve. Place the new
expansion valve in position.
6) Remove the drier, then place the new drier in position. Install the new drier with the
arrow on the drier in the direction of the refrigerant flow.
7) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.
WARNING
1. Do not heat the wall of the machine. Place a steel barrier for protection.
. Always protect the valve body by using a damp cloth to prevent the valve
from overheating. Do not braze with the valve body exceeding 50°F
(11°C).
8) Use an electronic leak detector or soap bubbles to check for leaks. Add a trace of
refrigerant to the system (if using an electronic leak detector), and then raise the
pressure using nitrogen gas (140 PSIG). DO NOT use R-404A as a mixture with
pressurized air for leak testing.
9) Evacuate the system and charge it with refrigerant. See the nameplate on the
condensing unit for the required refrigerant charge.
10) Attach the expansion valve bulb to the suction line in the same location as the previous
bulb. The bulb should be at the 1 o’clock position on the tube. Be sure to secure the
bulb with the clamp and holder and to insulate it.
11) Place the new expansion valve cover in position.
1) Replace the panels in their correct positions.
13) Turn on the power supply.
